I stayed at the Omega for a technical conference in Sophia Antipolis. The hotel is just down the hill from the ETSI headquarters and other technical research organizations - a 3- 5 minute walk. The room was fine, with slightly older furniture but a comfortable bed, and very clean. Reception staff were very friendly and helpful - they spoke English and French. There was an adjoining room, but as other reviews noted you could hear mildly muffled conversations through the door. This might bother some people, especially if the adjoining neighbors were noisy, but while it was at times intrusive, it wasn't a huge issue for me. Traffic noise was also noticeable at times, since my room faced the street.
The restaurant had a good breakfast ( at 13.50 euros extra charge) including sausages, juice, cheese, croissants, pastries, scrambled eggs, coffee etc. I had dinner twice at the restaurant - food was good, including a very nice array of salads and desserts, but the main course preparation (meats, fish) was not exceptional. Service was very friendly - restaurant was relaxed. My typical dinner cost about 25 euros with wine and bottled water. WIFi worked OK (extra charge of 20 euros for 10 hours). I was there on business, so the hotel was very convenient for me, and makes sense for those with a car or who need to be close to the research centers. But taxi from the Nice airport was extremely expensive - around 50 euros. There is a public bus (Number 230) for 1 euro from Nice airport (terminal 1 I believe) to Sophia Antipolis/Vabonne, with a stop close to the hotel, just a few minutes walk. I would recommend trying if you don't have a lot of luggage. All in all, a positive stay at a friendly hotel for my business trip.